Method of manufacturing refrigerating systems



W. B. ANDERSON March 24, 1942.

METHOD OF MANUFACTURING REFRIGERATING SYSTEMS Filed Oct. 25, 1940 I l I 1 lllld I N 4 O ,1. 1 a .wz \Ia. N: in .wm 1A m 5 MW m u l m. ww. w ML FIG. 3.

Patented Mar. 24, 1942 METHOD OF MANUFACTURING REFRIG- ERATING SYSTEMS William B. Anderson,

signor to Westinghouse West Springfield, Mass, as- Electric & Manufacturlng Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application October 25, 1940,

8 Claims.

My invention relates to a method of manufacturing refrigerating systems and particularly to a method of dehydrating refrigerating systems prior to charging them with refrigerant.

It is a primary object of my invention to provide improved dehydration of refrigerating sys terns, on a large production basis.

It is a further object of my invention to insure a flow of dry gas to all parts of a refrigerating system during dehydration, so that substantially all moisture is removed from every part of the system.

It is another object of my invention to accurately control the flow of dry gas through the refrigerating system during dehydration and to facilitate the testing of gas flow and ultimate dryness in the system.

It is still another object of my invention to provide a plurality of air flow paths through each refrigerating system and furthermore to provide for a flow of dry gas through a plurality of systems in series.

These and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawing forming a part of this application, in which:

Fig. 1 is a diagrammatic view of a refrigerating system with conduit connections so arranged that the gas fiows through the system in accordance with the present invention;

Fig. 2 is a diagrammatic view of a compressor showing the flow of gas therethrough; and,

Fig. 3 is a diagrammatic view of a plurality of the refrigerating systems shown in Fig. 1 connected in series and disposed in an oven.

Referring specifically to the drawing for a detailed description of my invention, a complete refrigerating system is designated by the numeral II and comprises a motor l2 which drives a compressor l3. A hermetically-sealed casing l4 encloses the motor and compressor. A conduit l1 at the motor end of the sealed casing I4 is open to atmosphere. A conduit 20 connects with an evaporator l6 and is connected to conduit l'l after dehydration to afford communication between the evaporator l6 and the interior of the sealed casing M. The evaporator I6 is also connected to a condenser 18 through a capillary tube flow-restricting device l9 and a screen element 2|, which are shown by way of example. The condenser I8 is connected to the discharge of the compressor l3 through a conduit 23, which conduit 23 is provided with a T- fltting 24. An open conduit 25 extends into the Serial No. 362,717

T-fitting 24 for a purpose hereinafter described.

The compressor l3 comprises a piston 26 which is reciprocated in a cylinder 21. A suction valve plate 28 is held in position between the cylinder 21 and a separator disk 3| and a discharge valve plate 32 is retained in position between disk 3| and a cylinder head 33. The compressor is provided with a suction inlet conduit 30 which is in open communication with the interior of the sealed casing l4. During dehydration, the motor l2 and compressor l3 are inactive.

The system thus described is dehydrated in the following manner: First the conduit 25 of the first unit is connected to the conduit ll ofthe second unit, and so on until seven or eight complete refrigerating systems are connected in series, as shown in Fig. 3. The conduit 20 is left open to atmosphere and at the end of the series, a restricting valve 35 is provided on conduit 25 of the last refrigerating system for a purpose hereinafter described. The series of refrigerating systems are then placed in a dehydrating oven, shown diagrammatically at 3 in Fig. 3, which is maintained at a predetermined elevated temperature around C. Dry gas, for example, air, at a predetermined pressure is then supplied to the open conduit ll of the first refrigerating system. While it is preferable to use dry gas at all times, this procedure is not absolutely essential, as ordinary room air may be used for several hours at the beginning of dehydration to sweep out the steam atmosphere generated by oven heat, and dry gas used only at the end of the dehydration period so that the air or gas remaining is as dry as the atmosphere in the individual units.

The gas then flows through each system in the following paths. All the gas is conveyed through the interior of the sealed casing It, first passing over the motor l2. The motor of the refrigerating system comprises a stator 36 and a rotor 31. The stator 36 is usually formed of a coil of wire which is covered, for example, by cotton or enamel insulation and the stator is the most difllcult part of the system to dry. Since all the gas is conveyed through the motor I2, proper drying thereof is insured.

After the gas leaves the motor l2, it enters the suction inlet conduit 30 of the compressor. The gas, naturally, is under positive pressure so that, as shown in Fig. 2, it depresses the suction valve 28, flows into the cylinder 21,,raises the discharge valve 32, and is discharged through conduit 23 which leads to the condenser 18. Most of the gas is conveyed through fitting 24 and conduit 25 to the next refrigerating system in the series, since conduit 25 of one system is connected to conduit ll of the next system. However, an appreciable amount or the gas circulates through passages 38 of the condenser, through screen element 2i, capillary tube l9, evaporator i6 and is discharged through the open conduit; 2i), thus dehydrating those parts of the system. The restricting valve 35 on the conduit 25 of the last refrigerating system in the series maintains a sufficient back pressure throughout the series of refrigeration systems to overcome the restriction of the capillary tubes i9 and to insure flow of gas By maintaining the gas inlet pressure within predetermined limits, and the flow of gas at the outlet of the last unit at a predetermined value, a definite supply of gas to all. the

units in the series is insured. As shown in Fig. 3, the gas is at a pressure of, for example, 17 lbs. per square inch gauge at the conduit it of the first unit and drops approximately 2 lbs. per square inch as it passes through each unit, the pressure in the last unit being about 2 lbs. per square inch gauge.

Several distinct advantages are realized by utilizing the gas flow just described. First, as stated hereinbefore, an adequate supply of gas is insured for drying the motor it, which is the most diilicult part of the system to dehydrate. Sec-- ondly, a flow of gas is insured through the con denser i8, capillary tube [9 and evaporator i since it is possible for an attendant to place his finger over the end of the conduit 20 and determine if gas is flowing therethrough; If the capillary tube or some other part of the passage is clogged, it will be ascertained at once and corrected. Therefore, proper dehydration is insured and systems with clogged capillary tubes or the like are discovered before the expense of charging the system with refrigerant and lubricant is incurred. Furthermore, the moisture contained in the passages 38 of condenser i8, capillary tube I9, evaporator l6 and conduit 20 is exhausted through conduit 2t and does not enter the next system in the series. In addition, because of the positive gas flow through all parts of every refrigerating system, and the ease of determining gas flow, the method is cheaper than former methods, results in less wet systems after charging with refrigerant and provides a better quality product on a large production basis.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What I claim is:

1. The method of dehydrating refrigeration apparatus before it is charged with a refrigerant, which refrigeration apparatus includes a motor, a compressor, a condenser, an evaporator, a flowrestricting device disposed between the condenser and evaporator and passages connecting said parts and forming therewith a circuit for the flow of gas, which method comprises passing gas first through said motor, exhausting a portion which has passed through said motor of said circuit before it enters the conevaporator, passing another portion of which has passed through said motor,

exteriorly denser or said gas, through the condenser, flow-restricting device then exhausting said latter exteriorly of said circuit before it enters the condenser or evaporator, passing another portion of said gas, which has passed through said motor and compressor, through the condenser, flow-restricting device and evaporator and then exhausting said latter gas from said circuit.

3. The method of dehydrating refrigeration apwith a refrigerant,

through said sealed casing, denser, flow-restricting device and evaporator and then exhausting said latter gas from said circuit.

the series, passing another portion of the gas, which has passed through the motor, through the condenser, flow-restricting device and evaporator oi the first system and exhausting said latter gas exteriorly of the gas circuit of the respective systems in said series.

6. The method of dehydrating a plurality of complete refrigerating systems before charging with refrigerant, each of said systems including a motor, a compressor, a condenser, an evaporator, a flow-restricting device between the condenser and the evaporator and passages connecting said parts and forming therewith a circuit for the flow of gas, which method comprises disposing the systems in a heated chamber, connecting said plurality of systems in series by conduit connections, passing gas first through the motor of the first refrigerating system, conveying a portion of the gas which has passed through said motor to the next refrigerating system in the series before said gas enters the condenser or evaporator of the first refrigerating system in the series, passing another portion of the gas, which has passed through the motor, through the condenser, fiow-restricting device and evaporator of the first system, exhausting said latter gas from said circuit exteriorly of the systems and repeating the aforesaid steps for each system in said series with the gas conveyed thereto from the prior system in the series.

7. The method of dehydrating a plurality of complete refrigerating systems before charging with refrigerant, each of said systems including a motor, a compressor, a hermetically-sealed casing enclosing the motor and compressor, a condenser, an evaporator, a flow-restricting device between the condenser and evaporator and passages connecting said parts and forming therewith a circuit for the flow of gas, which method comprises connecting said plurality of systems in series by conduit connections, passing gas first through the hermetically-sealed casing of the first refrigerating system to dry the motor and compressor contained therein, conveying a portion of the gas which has passed through said sealed casing to the next refrigerating system in the series before said gas enters the condenser or evaporator of the first refrigerating system in the series, passing another portion of the gas, which has passed through the sealed casing, through the condenser, flow-restricting device and evaporator of the first system, exhausting said latter gas from said circuit exteriorly of the respective systems and repeating the aforesaid steps for each system in said series with the gas conveyed thereto from the prior system of the series.

8. The method of dehydrating a plurality of complete refrigerating systems before charging with refrigerant, each of said systems including a motor, a compressor, a condenser, an evaporator, a flow-restricting device between the condenser and evaporator and passages connecting said parts and forming therewith a circuit for the flow of gas, which method comprises connecting said plurality of systems in series by conduit connections, passing gas first through the motor of the first refrigerating system, conveying a portion of the gas which has passed through said motor to the next refrigerating system in the series before said gas enters the condenser or evaporator of the first refrigerating system in the series, passing another portion of the gas, which has passed through the motor, through the condenser, fiow-restricting device and evaporator of the first system, exhausting said latter gas from said circuit exteriorly of the systems and repeating the aforesaid steps for each system in said series with the gas conveyed thereto from the prior system in the series.

WHLIAM B. ANDERSON. 

